<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		html{
			font-size:100px;
		}
		.div1{
			width: 1rem;
			height: 1rem;
		}
	</style>
</head>
<body>

	<div class="div1"></div>
</body>
</html>